融合依存句法的深度学习藏语句子分割研究

藏语句子分割是藏语自然语言处理中的一项重要且基础性的研究工作。该文根据藏语句子结构特征,在分析藏语句子分割规则与难点的基础上,提出一种融合依存句法的藏语句子分割模型。该模型首先通过词嵌入和藏语依存句法信息嵌入将输入序列映射成实值向量;然后构建融合藏语依存句法的双向LSTM,拼接词语和句法信息特征,提高上下文时序特征的学习能力;最后利用CRF预测出最佳句子分割点。通过对比实验,验证了该模型对藏语句子分割的有效性。实验结果表明,该模型的F₁值为99.4%。     

加快水利发展 建设美好西藏

2011年是“十二五”开局之年,也是西藏和平解放60周年。《中共西藏自治区委员会西藏自治区人民政府关于加快水利改革发展的意见》（藏党发[2011]6号）对西藏水利改革与发展提出了具体目标和政策措施。我们将按照“科学治水、依法治水、民生优先、生态为基”的要求．加快水利改革发展,促进西藏高原人水和谐。     

Variability and the genotypic effect on antioxidant activity,total phenolics,carotenoids and ascorbic acid content in seventeen natural population of Seabuckthorn (Hippophae rhamnoides L.) from trans-Himalaya

Seventeen natural population of Seabuckthorn (SBT), which comprised 187 plants from trans-Himalaya, were studied to find out variability and genotypic effect on total phenolic content (TPC), total antioxidant capacity (TAC), ascorbic acid and carotenoids content in fruit pulp. The fruits were found to be rich in TPC ranging from 964 to 10,704 mg gallic acid equivalent/100 g. The free radical-scavenging activity in terms of inhibitory concentration (IC₅₀) ranged from 0.7 to 9.1 mg/ml and ferric reducing antioxidant potential (FRAP) from 180 to 1355 FeSO₄·7H₂O μg/ml. The ascorbic acid and carotenoids content ranged from 56 to 3909 mg/100 g and 0.1–14.4 mg/100 g, respectively. A variation of 1–11 fold in TPC, 1–14 folds in IC₅₀ by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and 1–8 fold in ferric reducing antioxidant potential, 1–70 fold in ascorbic acid content and 1–206 fold in carotenoid content among the examined fruit across 17 populations underlines the important role played by genetic background and the geographical location for determining the health promoting compounds. Significant correlation was observed between TPC, IC₅₀, FRAP, carotenoids, ascorbic acid, fruit lightness (L*) and plant height. Among the 20 morphological traits studied, fruit colour and plant height showed positive correlation with the health promoting compounds.     

Machine intelligence-driven classification of cancer patients-derived extracellular vesicles using fluorescence correlation spectroscopy: results from a pilot study

Neural Computing and Applications - Patient-derived extracellular vesicles (EVs) that contains a complex biological cargo is a valuable source of liquid-biopsy diagnostics to aid in early...     

自然场景下乌金体藏文的检测与识别

自然场景乌金体藏文文本信息作为高度浓缩的高层语义信息,不仅具有较大的研究和实用价值,而且可以用于协助藏文场景文本理解领域的研究.目前针对自然场景下乌金体藏文的检测与识别的相关研究甚少,本文在人工收集的自然场景乌金体藏文图像数据集的基础上,对比了目前常见的文字检测算法在自然场景乌金体藏文上的检测性能以及在不同特征提取网络下基于序列的文字识别算法CRNN在自然场景乌金体藏文图像数据集上的识别准确率并分析了在314张真实自然场景下乌金体藏文识别出错的特殊例子.实验表明本文在文字检测阶段采用的可微分的二值化网络DBNet在测试集上具有更好的检测性能,该方法在测试集上的准确率、召回率、F1值分别达到了0.89、0.59、0.71;在文字识别阶段采用MobileNetV3 Large作为特征提取网络时,CRNN算法在测试集上的识别准确率最高,达到了0.4365.     

基于CRF的藏文地名识别技术研究

藏文地名识别是藏文命名实体识别中必须要解决的问题。通过分析藏文地名的特点及识别难点,阐述了藏文地名的音节、触发词、地名后续词和格助词等特性适用基于CRF模型的地名识别,通过实验,验证了6种特征对藏文地名识别的有效性。实验结果表明该方法对藏文地名识别的准确率、召回率和[F]值分别达到了96.12%、81.92%和88.45%,实验结果与已有的系统相比,取得了较好的效果。     

Microwave-Assisted Base-Free Oxidation of Glucose with H2O2 on Gold- and Manganese-Containing SBA-15—Insight into Factors Affecting the Reaction Pathway

The aim of this work was to gain insights into the role of manganese in MnSBA-15 support for gold in the base-free glucose oxidation with H₂O₂ using a microwave reactor. MnSBA-15 (manganese—acidity source) and SBA-15 (for comparison) were modified with Au (2.2 wt. %) and Cu (for comparison). The physicochemical properties of the catalysts were investigated by XRD, N₂ ads/des, TEM, UV-vis, XPS, pyridine adsorption combined with FTIR, ATR-FTIR, and 2-propanol decomposition. The effects of the Mn presence in the support, Au NPs size that determines the number of active Au centers, and the Fermi energy (E_F), together with the effects of the pore size, reaction temperature, and time on the activity and selectivity of the applied catalysts were assessed and discussed. It has been demonstrated that the presence of Mn generated Lewis acid centers which did not participate in glucose and H₂O₂ adsorption, and thus, were not directly involved in the reaction pathway. Both reagents were adsorbed on gold nanoparticles. H₂O₂ was decomposed to molecular oxygen which oxidized glucose to gluconic acid (50–90% of glucose conversion depending on the reaction time and ~100% selectivity). The presence of manganese in MnSBA-15 was responsible for increased Au NPs size and only slightly influenced the negative charge on gold particles. To achieve effective activity a compromise between the number of active gold species and the level of E_F has to be reached (for 5.7 nm Au NPs).     

Helen F. Stuart and Hannah Frances Green: The Original Spirit Photographer

Spirit photographs are joint portraits that visually unite the bereaved and the deceased without use of a corpse. Arising from the same ideas that founded Spiritualism in the nineteenth century, these enchanted mementos are said to have been discovered by William H. Mumler in 1861, in Boston, Massachusetts. Spirit photographers typically worked with mediums who enabled the appearance of magical ‘extras’ of the deceased, and as the majority of mediums were women, their contributions to this development within personal mourning rituals have been limited almost exclusively to this activity. Fuelled by the acknowledged proximity of two women to the invention, Helen F. Stuart and Hannah Frances Green, this article challenges Mumler’s widely accepted status as the originator of spirit photography. Although Stuart was the owner of the studios where Mumler stumbled upon his invention and Green was a secretary and medium in the same studios, scholars have tended to refuse these women larger roles. This article establishes the viability of a new narrative, presenting the strong likelihood that these women were in fact one and the same person and proposing that this woman be recognised as a pioneer of spirit photography.     

A comparative study on the magnetic properties of MFe12O19 and MAlFe11O19 (M = Sr, Ba and Pb) hexaferrites with different morphologies

M-type nano hexaferrites MFe₁₂O₁₉ and MAlFe₁₁O₁₉ (M = Sr, Ba and Pb) have been prepared by the sol-gel method to investigate the shielding effect of inorganic ions KCl, KBr and KI on the phase growth of ferrites. FTIR frequency bands in the range 560-580 cm⁻¹ and 430-470 cm⁻¹corresponds to the formation of tetrahedral and octahedral clusters of metal oxides in ferrites, respectively. X-ray powder diffractographs do not show any peaks for the as obtained samples showing the amorphous nature of the samples, however regular peaks for M-type structure have been obtained for all the annealed samples. There is negligible small change in the lattice parameters ‘a’ and ‘c’ with substitution of the hexagonal ferrites with aluminium. Magnetic measurements showed that the coercivity (Hc) values of all the samples with KCl and KBr enhance due to KCl and KBr to act as deactivators. However, the coercivity value decreases with KI as it oxidise to I₂ during annealing. The saturation magnetization of the hexaferrites decreases with Al³⁺ ion substitution for Fe³⁺ ion due to preferential occupancy of aluminium in octahedral sites.     

Structural,electrical and magnetic properties of Co0.5Zn0.5AlxFe2−xO4 (x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) prepared via sol–gel route

Nanoparticles of Co_0.5Zn_0.5Al_xFe_2?xO₄ (x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) were synthesized by sol–gel method and the influence of Al³⁺ doping on the properties of Co_0.5Zn_0.5Fe₂O₄ was studied. X-ray diffraction studies revealed the formation of single phase spinel type cubical structure having space group Fd-3m. A decreasing trend of the lattice parameter was observed with increasing Al³⁺ concentration due to the smaller ionic radii of Al³⁺ ion as compared to Fe³⁺ ion. TEM was used to characterize the microstructure of the samples and particle size determination, which exhibited the formation of spherical nanoparticles. The particle size was found to be increases up to ～45 nm after annealing the sample at 1000 °C. Electrical resistivity was found to increase with Al³⁺ doping, attributed to the decrease in the number of Fe²⁺–Fe³⁺ hopping. The activation energy decreased with increasing Al³⁺ ion concentration, indicating the blocking of conduction mechanism between Fe³⁺–Fe²⁺ ions. The value of saturation magnetization decreased, when Fe³⁺ ions were doped with Al³⁺ ions in Co_0.5Zn_0.5Fe₂O₄; however, the coercivity values increased with increasing Al³⁺ ion content.